diff --git a/vlib/builtin/map.v b/vlib/builtin/map.v
index 91e473e9e7..37b2e49317 100644
--- a/vlib/builtin/map.v
+++ b/vlib/builtin/map.v
@@ -338,7 +338,7 @@ fn new_map(key_bytes int, value_bytes int, hash_fn MapHashFn, key_eq_fn MapEqFn,
 		cached_hashbits: max_cached_hashbits
 		shift: init_log_capicity
 		key_values: new_dense_array(key_bytes, value_bytes)
-		metas: unsafe { &u32(vcalloc(metasize)) }
+		metas: unsafe { &u32(vcalloc_noscan(metasize)) }
 		extra_metas: extra_metas_inc
 		len: 0
 		has_string_keys: has_string_keys
diff --git a/vlib/builtin/map_d_gcboehm_opt.v b/vlib/builtin/map_d_gcboehm_opt.v
new file mode 100644
index 0000000000..93049b7212
--- /dev/null
+++ b/vlib/builtin/map_d_gcboehm_opt.v
@@ -0,0 +1,146 @@
+// "noscan" versions of `map` initialization routines
+//
+// They are used when the compiler can proof that either the keys or the values or both
+// do not contain any pointers. Such objects can be placed in a memory area that is not
+// scanned by the garbage collector
+
+module builtin
+
+[inline]
+fn new_dense_array_noscan(key_bytes int, key_noscan bool, value_bytes int, value_noscan bool) DenseArray {
+	cap := 8
+	keys := if key_noscan {
+		unsafe { malloc_noscan(cap * key_bytes) }
+	} else {
+		unsafe { malloc(cap * key_bytes) }
+	}
+	values := if value_noscan {
+		unsafe { malloc_noscan(cap * value_bytes) }
+	} else {
+		unsafe { malloc(cap * value_bytes) }
+	}
+	return DenseArray{
+		key_bytes: key_bytes
+		value_bytes: value_bytes
+		cap: cap
+		len: 0
+		deletes: 0
+		all_deleted: 0
+		keys: keys
+		values: values
+	}
+}
+
+fn new_map_noscan_key(key_bytes int, value_bytes int, hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn) map {
+	metasize := int(sizeof(u32) * (init_capicity + extra_metas_inc))
+	// for now assume anything bigger than a pointer is a string
+	has_string_keys := key_bytes > sizeof(voidptr)
+	return map{
+		key_bytes: key_bytes
+		value_bytes: value_bytes
+		even_index: init_even_index
+		cached_hashbits: max_cached_hashbits
+		shift: init_log_capicity
+		key_values: new_dense_array_noscan(key_bytes, true, value_bytes, false)
+		metas: unsafe { &u32(vcalloc_noscan(metasize)) }
+		extra_metas: extra_metas_inc
+		len: 0
+		has_string_keys: has_string_keys
+		hash_fn: hash_fn
+		key_eq_fn: key_eq_fn
+		clone_fn: clone_fn
+		free_fn: free_fn
+	}
+}
+
+fn new_map_noscan_value(key_bytes int, value_bytes int, hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn) map {
+	metasize := int(sizeof(u32) * (init_capicity + extra_metas_inc))
+	// for now assume anything bigger than a pointer is a string
+	has_string_keys := key_bytes > sizeof(voidptr)
+	return map{
+		key_bytes: key_bytes
+		value_bytes: value_bytes
+		even_index: init_even_index
+		cached_hashbits: max_cached_hashbits
+		shift: init_log_capicity
+		key_values: new_dense_array_noscan(key_bytes, false, value_bytes, true)
+		metas: unsafe { &u32(vcalloc_noscan(metasize)) }
+		extra_metas: extra_metas_inc
+		len: 0
+		has_string_keys: has_string_keys
+		hash_fn: hash_fn
+		key_eq_fn: key_eq_fn
+		clone_fn: clone_fn
+		free_fn: free_fn
+	}
+}
+
+fn new_map_noscan_key_value(key_bytes int, value_bytes int, hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn) map {
+	metasize := int(sizeof(u32) * (init_capicity + extra_metas_inc))
+	// for now assume anything bigger than a pointer is a string
+	has_string_keys := key_bytes > sizeof(voidptr)
+	return map{
+		key_bytes: key_bytes
+		value_bytes: value_bytes
+		even_index: init_even_index
+		cached_hashbits: max_cached_hashbits
+		shift: init_log_capicity
+		key_values: new_dense_array_noscan(key_bytes, true, value_bytes, true)
+		metas: unsafe { &u32(vcalloc_noscan(metasize)) }
+		extra_metas: extra_metas_inc
+		len: 0
+		has_string_keys: has_string_keys
+		hash_fn: hash_fn
+		key_eq_fn: key_eq_fn
+		clone_fn: clone_fn
+		free_fn: free_fn
+	}
+}
+
+fn new_map_init_noscan_key(hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn, n int, key_bytes int, value_bytes int, keys voidptr, values voidptr) map {
+	mut out := new_map_noscan_key(key_bytes, value_bytes, hash_fn, key_eq_fn, clone_fn,
+		free_fn)
+	// TODO pre-allocate n slots
+	mut pkey := &byte(keys)
+	mut pval := &byte(values)
+	for _ in 0 .. n {
+		unsafe {
+			out.set(pkey, pval)
+			pkey = pkey + key_bytes
+			pval = pval + value_bytes
+		}
+	}
+	return out
+}
+
+fn new_map_init_noscan_value(hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn, n int, key_bytes int, value_bytes int, keys voidptr, values voidptr) map {
+	mut out := new_map_noscan_value(key_bytes, value_bytes, hash_fn, key_eq_fn, clone_fn,
+		free_fn)
+	// TODO pre-allocate n slots
+	mut pkey := &byte(keys)
+	mut pval := &byte(values)
+	for _ in 0 .. n {
+		unsafe {
+			out.set(pkey, pval)
+			pkey = pkey + key_bytes
+			pval = pval + value_bytes
+		}
+	}
+	return out
+}
+
+fn new_map_init_noscan_key_value(hash_fn MapHashFn, key_eq_fn MapEqFn, clone_fn MapCloneFn, free_fn MapFreeFn, n int, key_bytes int, value_bytes int, keys voidptr, values voidptr) map {
+	mut out := new_map_noscan_key_value(key_bytes, value_bytes, hash_fn, key_eq_fn, clone_fn,
+		free_fn)
+	// TODO pre-allocate n slots
+	mut pkey := &byte(keys)
+	mut pval := &byte(values)
+	for _ in 0 .. n {
+		unsafe {
+			out.set(pkey, pval)
+			pkey = pkey + key_bytes
+			pval = pval + value_bytes
+		}
+	}
+	return out
+}
diff --git a/vlib/v/gen/c/cgen.v b/vlib/v/gen/c/cgen.v
index fc04e0e0d2..73ad9f4638 100644
--- a/vlib/v/gen/c/cgen.v
+++ b/vlib/v/gen/c/cgen.v
@@ -4335,11 +4335,22 @@ fn (mut g Gen) map_init(node ast.MapInit) {
 		styp = g.typ(node.typ)
 		g.write('($styp*)memdup(ADDR($styp, ')
 	}
+	noscan_key := g.check_noscan(node.key_type)
+	noscan_value := g.check_noscan(node.value_type)
+	mut noscan := if noscan_key.len != 0 || noscan_value.len != 0 { '_noscan' } else { '' }
+	if noscan.len != 0 {
+		if noscan_key.len != 0 {
+			noscan += '_key'
+		}
+		if noscan_value.len != 0 {
+			noscan += '_value'
+		}
+	}
 	if size > 0 {
 		if value_typ.kind == .function {
-			g.write('new_map_init($hash_fn, $key_eq_fn, $clone_fn, $free_fn, $size, sizeof($key_typ_str), sizeof(voidptr), _MOV(($key_typ_str[$size]){')
+			g.write('new_map_init${noscan}($hash_fn, $key_eq_fn, $clone_fn, $free_fn, $size, sizeof($key_typ_str), sizeof(voidptr), _MOV(($key_typ_str[$size]){')
 		} else {
-			g.write('new_map_init($hash_fn, $key_eq_fn, $clone_fn, $free_fn, $size, sizeof($key_typ_str), sizeof($value_typ_str), _MOV(($key_typ_str[$size]){')
+			g.write('new_map_init${noscan}($hash_fn, $key_eq_fn, $clone_fn, $free_fn, $size, sizeof($key_typ_str), sizeof($value_typ_str), _MOV(($key_typ_str[$size]){')
 		}
 		for expr in node.keys {
 			g.expr(expr)
@@ -4359,7 +4370,7 @@ fn (mut g Gen) map_init(node ast.MapInit) {
 		}
 		g.write('}))')
 	} else {
-		g.write('new_map(sizeof($key_typ_str), sizeof($value_typ_str), $hash_fn, $key_eq_fn, $clone_fn, $free_fn)')
+		g.write('new_map${noscan}(sizeof($key_typ_str), sizeof($value_typ_str), $hash_fn, $key_eq_fn, $clone_fn, $free_fn)')
 	}
 	if g.is_shared {
 		g.write('}, sizeof($shared_styp))')
@@ -6076,7 +6087,18 @@ fn (mut g Gen) type_default(typ_ ast.Type) string {
 			info := sym.map_info()
 			key_typ := g.table.get_type_symbol(info.key_type)
 			hash_fn, key_eq_fn, clone_fn, free_fn := g.map_fn_ptrs(key_typ)
-			init_str := 'new_map(sizeof(${g.typ(info.key_type)}), sizeof(${g.typ(info.value_type)}), $hash_fn, $key_eq_fn, $clone_fn, $free_fn)'
+			noscan_key := g.check_noscan(info.key_type)
+			noscan_value := g.check_noscan(info.value_type)
+			mut noscan := if noscan_key.len != 0 || noscan_value.len != 0 { '_noscan' } else { '' }
+			if noscan.len != 0 {
+				if noscan_key.len != 0 {
+					noscan += '_key'
+				}
+				if noscan_value.len != 0 {
+					noscan += '_value'
+				}
+			}
+			init_str := 'new_map${noscan}(sizeof(${g.typ(info.key_type)}), sizeof(${g.typ(info.value_type)}), $hash_fn, $key_eq_fn, $clone_fn, $free_fn)'
 			if typ.has_flag(.shared_f) {
 				mtyp := '__shared__Map_${key_typ.cname}_${g.table.get_type_symbol(info.value_type).cname}'
 				return '($mtyp*)__dup_shared_map(&($mtyp){.mtx = {0}, .val =$init_str}, sizeof($mtyp))'
diff --git a/vlib/v/markused/markused.v b/vlib/v/markused/markused.v
index 21c081b4a3..989d41c6f7 100644
--- a/vlib/v/markused/markused.v
+++ b/vlib/v/markused/markused.v
@@ -21,7 +21,10 @@ pub fn mark_used(mut table ast.Table, pref &pref.Preferences, ast_files []&ast.F
 		'__new_array_with_default',
 		'__new_array_with_array_default',
 		'v_realloc' /* needed for _STR */,
-		'v_malloc' /* needed for _STR */,
+		'malloc',
+		'malloc_noscan',
+		'vcalloc',
+		'vcalloc_noscan',
 		'new_array_from_c_array',
 		'v_fixed_index',
 		'memdup',